Transmission of Microwaves Through a Dynamic Corn Canopy in Emission Models

In this paper, we develop a canopy opacity model for sweet corn. The model, calculated using a simple refractive emission model, is based upon observed moisture distribution in the corn canopy for vegetative and reproductive stages during our Fourth Microwave Water and Energy Balance Experiment (MicroWEX-4). The moisture content decreases linearly with height of the corn height during the vegetative stages. During the reproductive stage, the moisture distribution in the fruit region can be estimated as Gaussian, with the spread dependent on grain biomass. The optical depth increased during the growing season to a maximum of 1.34 on DoY 153, corresponding to the canopy biomass of 3.48 kg/m² and canopy height of 1.72 m.